Fig. 5.

Stimulated insulin secretion is reduced in isolated synaptotagmin-7 mutant mouse islets. (A) Glucose-induced insulin secretion from isolated islets was measured in perifusion experiments at a glucose concentration of 3 mM (basal) or 20 mM (stimulatory). The perfusate was collected in 3-min intervals, and insulin levels were determined by using ELISA. Synaptotagmin-7 mutant islets (Syt7^−/−, filled square) displayed impaired insulin secretion when compared with control (open square). (B) Glucose-induced insulin secretion for the entire stimulation period (Total) or the first phase (during the first 15 min after stimulation) in the perifusion experiments was lower in isolated islets from mutant (gray bar) than from control (white bar). Insulin secretion was calculated by integrating the area under each curve in A after baseline subtraction. Data are presented as mean ± SEM. n = 9 for mutant and 10 for control. ∗, P < 0.05.